Spectral estimates for periodic Jacobi matrices

E. Korotyaev, I. V. Krasovsky

We obtain bounds for the spectrum and for the total width of the spectral gaps for Jacobi matrices on ${\ell }^2(\mathbb{Z})$ of the form $(H\psi {)}_n=a_{n-1}{\psi }_{n-1}+b_n{\psi }_n+a_n{\psi }_{n+1}$, where $a_…